Pyramidal mirror laser scanning for lidar

ABSTRACT

An apparatus includes a detector and a light source configured to emit light. The apparatus further includes a disk with a set of prisms and that is configured to rotate, arranged to receive and direct the emitted light, and arranged to receive and direct backscattered light. The apparatus further includes a reflecting apparatus with multiple reflective facets and configured to rotate, arranged to reflect the emitted light, and arranged to reflect the backscattered light. A focusing apparatus is arranged to focus the backscattered light from the disk towards the detector.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. patent application Ser. No.16/248,555, filed Jan. 15, 2019, which is incorporated herein byreference in its entirety for all purposes.

SUMMARY

In Example 1, an apparatus includes a detector; a light sourceconfigured to emit light; a disk having a set of prisms, beingconfigured to rotate, arranged to receive and direct the emitted light,and arranged to receive and direct backscattered light; a reflectingapparatus having multiple reflective facets, being configured to rotate,arranged to reflect the emitted light, and arranged to reflect thebackscattered light; and a focusing apparatus arranged to focus thebackscattered light from the disk towards the detector.

In Example 2, the apparatus of Example 1, wherein the focusing apparatusis a curved mirror or a lens.

In Example 3, the apparatus of Example 1, wherein the focusing apparatusis a curved mirror, the apparatus further comprising a lens arranged tofocus the backscattered light reflected by the curved mirror towards thedetector.

In Example 4, the apparatus of any of Examples 1-3, further comprising aflat surface mirror arranged to reflect the backscattered light from thedisk towards a lens, wherein the lens is arranged to focus thebackscattered light towards the detector.

In Example 5, the apparatus of any of Examples 1-4, wherein the focusingapparatus includes an aperture through which the emitted light passes.

In Example 6, the apparatus of any of Examples 1-5, wherein the detectoris a single detector.

In Example 7, the apparatus of any of Examples 1-6, further comprising areflector arranged to reflect light from the light source towards theplurality of disks.

In Example 8, the apparatus of Example 7, wherein the reflector is arotatable mirror.

In Example 9, the apparatus of any of Examples 1-8, further comprising abeam splitter configured to split the emitted light from the light intoa number of separate light beams, wherein each of the number of beams isdirected to different reflective facets of the reflecting apparatus at agiven position of the reflecting apparatus.

In Example 10, the apparatus of Example 9, wherein the apparatuscomprises a plurality of detectors equal in number to the number ofseparate light beams created by the beam splitter.

In Example 11, the apparatus of any of Examples 1-5 and 7-10, wherein anumber of detectors is equal to a number of light sources.

In Example 12, the apparatus of any of Examples 1-11, wherein a numberof reflective facets of the reflecting apparatus is 6-12.

In Example 13, the apparatus of any of Examples 1-12, wherein the diskincludes multiple sets of prisms each with prisms having different prismangles from the other sets of prisms.

In Example 14, the apparatus of any of Examples 1-13, further comprisinga housing including a base member and a transparent cover that at leastpartially encompass an internal cavity, wherein the detector, the lightsource, the disk, and the focusing apparatus are positioned within theinternal cavity.

In Example 15, a method for generating a scanning light pattern isdisclosed. The method includes rotating a disk having prisms; rotating areflecting apparatus having multiple reflective facets; directing lightfrom a light source through the rotating disk to create a first lightpattern; and reflecting, via the rotating reflecting apparatus, thefirst light to generate the scanning light pattern.

In Example 16, the method of Example 15, further comprising receiving,at a detector, backscattered light of the generated scanning lightpattern that is reflected by the rotating reflecting apparatus and thatpasses through the disk.

In Example 17, the method of any of Examples 15 and 16, furthercomprising focusing, with a focusing apparatus, the backscattered lightthat has been reflected by the rotating reflecting appataus and that haspassed through the disk towards the detector.

In Example 18, an apparatus includes a detector; a light sourceconfigured to emit light; a first disk having a first set of prisms,being configured to rotate, arranged to receive and direct the emittedlight, and arranged to receive and direct backscattered light; a seconddisk having a multiple sets of prisms, being configured to rotate,arranged to receive and direct the emitted light, and arranged toreceive and direct backscattered light; a stationary reflectingapparatus arranged to reflect the emitted light and arranged to reflectthe backscattered light; and a focusing apparatus arranged to focus thebackscattered light towards the detector.

In Example 19, the apparatus of Example 18, wherein the stationarymirror is a conical-shaped mirror.

In Example 20, the apparatus of any of Examples 18 and 19, wherein themultiple sets of prisms on the second disk each have the same area ofthe other sets of prisms.

In Example 21, the apparatus or methods of any of Examples 1-20, whereinthe prisms are Fresnel prisms.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic, cut-away view of a measurement device, inaccordance with certain embodiments of the present disclosure.

FIG. 2 shows a perspective view of a disk capable of use in measurementdevices, in accordance with certain embodiments of the presentdisclosure.

FIG. 3 shows close-up, cut-away views of a portion of a disk capable ofuse in measurement devices, in accordance with certain embodiments ofthe present disclosure.

FIG. 4 shows a perspective view of a reflecting apparatus and a motor,in accordance with certain embodiments of the present disclosure.

FIG. 5 shows an exemplary schematic of a scanning path generated by themeasurement device of FIG. 1, in accordance with certain embodiments ofthe present disclosure.

FIGS. 6A and 6B show schematic, perspective views of the measurementdevice of FIG. 1 and exemplary scanning paths generated by themeasurement device, in accordance with certain embodiments of thepresent disclosure.

FIG. 7 shows a schematic, cut-away view of another measurement device,in accordance with certain embodiments of the present disclosure.

FIG. 8 shows a perspective view of a curved mirror capable of use inmeasurement devices, in accordance with certain embodiments of thepresent disclosure.

FIG. 9 shows a schematic, cut-away view of another measurement device,in accordance with certain embodiments of the present disclosure.

FIG. 10 shows a schematic, top view of portions of the measurementdevice of FIG. 9, in accordance with certain embodiments of the presentdisclosure.

FIG. 11 shows a schematic, cut-away view of another measurement device,in accordance with certain embodiments of the present disclosure.

FIG. 12 shows an exemplary schematic of a scanning path generated by themeasurement device of FIG. 11, in accordance with certain embodiments ofthe present disclosure.

FIG. 13 shows a schematic, cut-away view of another measurement device,in accordance with certain embodiments of the present disclosure.

FIG. 14 shows an exemplary schematic of a scanning path generated by themeasurement device of FIG. 13, in accordance with certain embodiments ofthe present disclosure.

FIG. 15 shows a schematic, cut-away view of another measurement device,in accordance with certain embodiments of the present disclosure.

FIG. 16 shows a schematic, top view of portions of the measurementdevice of FIG. 15, in accordance with certain embodiments of the presentdisclosure.

FIG. 17 shows a top view of a disk that can be used in the variousmeasurement devices, in accordance with certain embodiments of thepresent disclosure.

FIG. 18 shows a schematic, cut-away view of another measurement device,in accordance with certain embodiments of the present disclosure.

FIG. 19 shows a top view of one of the disks used in the measurementdevice of FIG. 18, in accordance with certain embodiments of the presentdisclosure.

FIG. 20 shows a schematic, cut-away view of another measurement device,in accordance with certain embodiments of the present disclosure.

FIG. 21 shows a top view of one of the disks used in the measurementdevice of FIG. 20, in accordance with certain embodiments of the presentdisclosure.

FIGS. 22A and 22B show schematic, cut-away views of another measurementdevice showing alternative arrangements of optical elements within themeasurement device, in accordance with certain embodiments of thepresent disclosure.

FIG. 23 shows a schematic, cut-away view of another measurement device,in accordance with certain embodiments of the present disclosure.

FIG. 24 shows a measurement device with an alternative arrangement ofvarious optical components, including multiple light sources, that canbe incorporated into other measurement devices described herein, inaccordance with certain embodiments of the present disclosure.

While the disclosure is amenable to various modifications andalternative forms, specific embodiments have been shown by way ofexample in the drawings and are described in detail below. Theintention, however, is not to limit the disclosure to the particularembodiments described but instead is intended to cover allmodifications, equivalents, and alternatives falling within the scope ofthe appended claims.

DETAILED DESCRIPTION

Certain embodiments of the present disclosure relate to measurementdevices and techniques, particularly, measurement devices and techniquesfor light detection and ranging, which is commonly referred to as LIDAR,LADAR, etc.

Current LIDAR devices such as those used in time-of-flight-based systemstypically use a series of spinning mirrors that steer many narrow lightbeams. These devices utilize a low numerical aperture, such that only asmall amount of reflected light is received by detectors within thedevice. As a result, these devices require very sensitive detectors.Certain embodiments of the present disclosure are accordingly directedto devices and techniques for measurement systems, such as LIDARsystems, in which sensors with a broader range of sensitivities can beused while still achieving accurate measurements. Further, as will bedescribed in more detail below, the disclosed measurement devicesinclude optical elements and arrangements that can be used to generatescanning patterns of light (e.g., paths along which light is scanned)with a large two-dimensional field of view using as few as one lightsource and to detect backscattered light using as few as one detector.

FIG. 1 shows a schematic of a measurement device 100 (e.g., aLIDAR/LADAR device) including a housing 102 with a base member 104 and acover 106. The base member 104 and the cover 106 can be coupled togetherto surround an internal cavity 108 in which various components of themeasurement device 100 are positioned. Various surfaces of components ofthe housing 102 can be coated with a light-absorbing or anti-reflectivecoating. In certain embodiments, the base member 104 and the cover 106are coupled together to create an air-tight seal and/or water-tightseal. For example, various gaskets or other types of sealing members canbe used to help create such seals between components of the housing 102.The base member 104 can comprise materials such as plastics and/ormetals (e.g., aluminum). The cover 106 can comprise transparentmaterials such as glass or sapphire. For simplicity, the housing 102 inFIG. 1 is shown with only the base member 104 and the cover 106, but thehousing 102 can comprise any number of components (e.g., fasteners,seals) that can be assembled together to surround the internal cavity108 and/or secure components of the measurement device 100. Further, thebase member 104 may be machined, molded, or otherwise shaped to supportand/or secure the components of the measurement device 100.

The figures are intended to show examples of how the features of themeasurement devices can be arranged to create scanning patterns of lightthat are emitted from and scattered back to the measurement devices. Forexample, the figures show how the features of the measurement devicescan be physically arranged with respect to each. Further, the figuresshow example arrangements and orientations of optical elements withinoptical paths that create patterns of light and collect, redirect,focus, and/or detect light scattered back to the measurement devices. Aswill be described further below, the arrangements and orientations ofoptical elements can be modified from the arrangements and orientationsin the Figures without departing from the scope of the presentdisclosure. Further yet, the features of the various measurement devicesshown and described below can be combined and/or interchanged with othermeasurement devices.

The measurement device 100 includes a light source 110 (e.g., a laser;LED), a disk 112 (e.g., a rotatable disk), a first reflecting apparatus114 (e.g., beam-steering device; a rotatable pyramidal-shaped mirror), asecond reflecting apparatus 116 (e.g., a stationary mirror), a focusingapparatus 118 (e.g., a lens; a curved mirror such as a parabolicmirror), and a detector 120 (e.g., a sensor).

The light source 110 can be a laser (e.g., a laser such as a VCSEL andthe like) or a light-emitting diode. In certain embodiments, the lightemitted is coherent light. In certain embodiments, the light source 110emits light within the infrared spectrum (e.g., 905 nm or 1550 nmfrequencies) while in other embodiments the light source 110 emits lightwithin the visible spectrum (e.g., a 485 nm frequency). In certainembodiments, the light source 110 is configured to emit light in pulses.Non-limiting examples of pulse rates for the light source 110 include100-1000 kHz, 200-800 kHz, and 300-600 kHz. Although the measurementdevices described herein reference are typically described in thecontext of pulsed, time-of-flight LIDAR approaches, the measurementdevices can be used for continuous-wave LIDAR, frequency-modulatedLIDAR, amplitude-modulated LIDAR, etc., as well. Further, although onlyone light source 110 is shown in FIG. 1, multiple light sources, beamsplitters, and/or optical switches can be used with the measurementdevice 100. In embodiments with multiple light sources, the lightsources can be pulsed asynchronously to avoid intereference orcross-talk at the one or more detectors. In certain embodiments usingmultiple light beams, the different light beams can be timed to firewithin certain angular positions of the disk 112.

The light emitted by the light source 110 is directed towards the disk112. The emitted light is represented in FIGS. 1-3 by reference number122. The disk 112 includes at least one set of prisms 124 (e.g., Fresnelprisms). In certain embodiments, including embodiments describing othermeasurement devices herein, the disk 112 can be considered to be adisk-shaped Fresnel prism. FIG. 2 shows a perspective view of the disk112 with an example set of prisms 124, and FIG. 3 shows a close-up sideview of the prisms 124. Although FIG. 2 shows the prisms 124 onlyextending over a portion of one side of the disk 112, the prisms 124 canextend over the entire upper surface (as shown in FIG. 1) and/or theentire lower surface of the disk 112. FIG. 3 shows each of the prisms124 having the same prism angle (PA). Example prism angles can rangefrom 0.5-30 degrees, 2-15 degrees, 5-15 degrees.

The disk 112 can be comprised of one or more transparent materials suchas glass, sapphire, and polymers (e.g., polycarbonate, high-indexplastics) and can be coated with an anti-reflective coating. The disk112 and/or the prisms 124 can be made via molding, three-dimensionalprinting, etching, machining, and the like. For example, the disk 112may be comprised of a planar disk substrate with the prisms 124 printedthereon or otherwise attached thereto. The diameter of the disk 112 canvary depending on the application, size of the measurement device 100,and other constraints such as available power or desired powerconsumption to rotate the disk 112. In certain embodiments, the disk 112is 60-80 mm in diameter.

The disk 112 is configured to rotate around an axis 126. The measurementdevice 100 can include a motor 128 (schematically shown in FIG. 1) thatrotates the disk 112. For example, the motor 128 can be coupled to ashaft 130 that coupled to the disk 112 at a central portion of the disk112 (e.g., at a central aperture of the disk 112). In another example,the motor 128 surrounds the disk 112 and is coupled to an outercircumference of the disk 112. The motor 128 can be afluid-dynamic-bearing motor, a ball-bearing motor, and the like.

As the disk 112 rotates, the emitted light 122 is deflected in athree-dimensional cone pattern resulting in a two-dimensional circlewithin a plane as shown in FIG. 5. The emitted light 122 deflected bythe disk 112 is then directed towards the rotating mirror 114.

An exemplary rotating mirror 114 is shown in FIG. 4 can be described asa six-sided (or hexagonal) pyramidal-shaped rotating mirror. Therotating mirror 114 can be at least partially created usingthree-dimensional printing, molding, machining, and the like. Therotating mirror 114 is coupled to a motor 132 that rotates the rotatingmirror 114 during operation of the measurement device 100. In certainembodiments, the motor 132 is directly coupled to a central aperture ofthe rotating mirror 114. In other embodiments, the motor 132 rotates ashaft that is coupled to the rotating mirror 114. The motor 132 can be afluid-dynamic-bearing motor, a ball-bearing motor, and the like.Although the motor 132 is shown as being centrally positioned within therotating mirror 114, the rotating mirror 114 can be rotated via othermeans. The rotating mirror 114 and the disk 112 can be rotatedindependly from each other such that they rotate in the same ordifferent directions and/or the same or different speeds. In certainembodiments, the motor 132 that rotates the rotating mirror 114 and themotor 128 that rotates the disk 112 are coaxial. In such embodiments,one of the motors and shafts may be sized such that it extends throughthe other motor and/or the other shaft.

Increasing rotational speed of the motor 132 (and therefore therotational speed of the rotating mirror 114) increases the sampling rateof the measurement device 100 but also increases the power consumed bythe measurement device 100. In certain embodiments, the disk 112 isrotated at a lower speed than the rotating mirror 114. Non-limitingexamples of rotating speeds for the disk 112 include 50-1000 rpm,100-800 rpm, and 300-600 rpm for low-speed applications and60,000-120,000 rpm for high-speed applications. Non-limiting examples ofrotating speeds for the rotating mirror 114 include 500-15,000 rpm,1,000-13,000 rpm, and 5,000-11,000 rpm.

The rotating mirror 114 comprises a plurality of facets/faces 134A-F.Each facet 134A-F includes or otherwise incorporates a reflectivesurface such as a mirror. For example, a separate mirror can be attachedto each facet 134A-F of the rotating mirror 114. Although the rotatingmirror 114 is shown and described as having six facets 134A-F at anapproximately 45-degree angle, the reflecting apparatus can have feweror more facets (e.g., 3-5 facets, 6-9 facets, 7-24 facets) at differentangles (e.g., 30-60 degrees). Further, one or more facets 134A-F can beat different angles than the other facets 134A-F. For example, facet134A may be angled at 41 degrees with respect to an axis perpendicularto the axis 126, facet 134B at 42.5 degrees, facet 134C at 44 degrees,facet 134D at 45.5 degrees, facet 134E at 47 degrees, and facet 134F at48.5 degrees. As another non-limiting example, each facet 134A-F canalternate between angles (e.g., facets 134A, 134C, and 134E angled at42.5 degrees, and facets 134B, 134D, and 134F angled at 47.5 degrees).The angle of the facets 134A-F affects what portion within the totalfield of view of the measurement device 100 the emitted light 122 isscanned along. The number of facets affects the displacement of theemitted light 122. For example, as the rotating mirror 114 rotates, theemitted light 122 directed towards the rotating mirror 114 (e.g., theemitted light 122 steered in a circle pattern by the rotating disk 112)will be reflected and scanned horizontally, and the extent of the scanin the horizontal direction as described in more detil immediatelybelow.

FIGS. 6A and 6B show two example light patterns 136A, 136B created overtime when the emitted light 122 from the disk 112 is reflected by therotating mirror 114. The light pattern 136A shown in FIG. 6A is createdover time as the emitted light 122 is scanned along a first half of thecircle shown in FIG. 5, and the light pattern 136B shown in FIG. 6B iscreated over time as the emitted light 122 is scanned along the otherhalf of the circle shown in FIG. 5. The light patterns 136A, 136B haverespective vertical components 138A, 138B and respective horizontalcomponents 140A, 140B that make up the field of view of the measurementdevice 100 in which the emitted light 122 is scanned throughout overtime as the measurement device operates. The vertical component 138A,138B of the light patterns 136A, 136B is dependent, among other things,on the prism angle PA of the prisms 124 on the disk 112. The horizontalcomponent 140A, 140B of the light patterns 136A, 136B is dependent onthe number of facets on the rotating mirror 114. For example, when therotating mirror 114 includes six facets, 134A-F, the emitted light 122from a single light beam is scanned along a sixty-degree displacement(i.e., 360 degrees divided by the number of facets, which is six for therotating mirror 114 shown in FIG. 4). This displacement affects thefield of view of the measurement device 100. Directing separate lightbeams to additional facets of the rotating mirror 114 can extend thehorizontal component 140A, 140B of the field of view (e.g., directinglight to two of the six facets results in a 120-degree displacement). Inaddition to extending the field of view, using additional light beamscan be used to reduce the speed required to rotate the rotating mirror114 and/or disk 112 for accomplishing a given frame rate of themeasurement device 100. As will be described in more detail below,creating additional light beams can be accomplished by adding additionallight sources and/or light beams via beam splitters and/or opticalswitches. Using fewer facets on the rotating mirror 114 can also extendthe horizontal component 140A, 140B of the field of view (e.g., fivefacets results in a 72-degree displacement).

The emitted light 122 is transmitted out of the housing 102 (e.g.,through the cover 106) of the measurement device 100 towards objects. Aportion of the emitted light reflects off the objects and returnsthrough the cover 106. This light, referred to as backscattered light,is represented in FIG. 1 by reference number 142 (not all of thebackscattered light is associated with a reference number in FIG. 1).The backscattered light 142 is reflected by the rotating mirror 114through the disk 112 and towards the stationary mirror 116. In certainembodiments, the backscattered light 142 is reflected by the same faceton the rotating mirror 114 that the emitted light 122 reflected againstbefore being transmitted out of the housing 102. The backscattered light142 may be redirected in an optical path that is parallel to theoriginal optical path. As such, the measurement device 100 does notrequire use of an arrary of multiple detectors. Instead, as will bediscussed in more detail below, the measurement device 100 can use asfew as a single detector even when the measurement devices utilizemultiple light paths, examples of which are shown in Figures discussedin more detail below.

The stationary mirror 116 can be a front surface mirror that is angledand positioned with respect to the rotatable mirror 114 to reflect thebackscattered light 142 towards the focusing apparatus 118. In FIG. 1,the direction of backscattered light 142 is modified by approximately 90degrees, although other angles can be used depending on the orientationof the focusing apparatus 118 and the detector 120. The stationarymirror 116 can include an aperture 144 to permit the emitted light 122from the light source 110 to pass through the stationary mirror 116 tothe disk 112. Although, in certain embodiments, the stationary mirror116 can help reduce the overall size of the measurement device 100, insome embodiments, various components of the measurement device 100 arearranged such that the measurement device 100 does not include thestationary mirror 116. One such example is shown in FIG. 24.

The backscattered light 142 reflected by the stationary mirror 116 isfocused by the focusing apparatus 118. The focusing apparatus 118 is anoptical element that focuses the backscattered light 142 towards thedetector 120. For example, the focusing apparatus 118 can be a lens witha focal point positioned at the detector 120. The particular shape,size, position, and orientation of the focusing apparatus 118 and thedetector 120 in the measurement device 100 can depend on, among otherthings, where the path(s) at which backscattered light 142 is directedwithin the housing 102, and space constraints of the measurement device100.

In certain embodiments, the focusing apparatus 118 focuses thebackscattered light 142 to a single detector 120, such as a singlephotodetector/sensor (e.g., single-element detector). In otherembodiments, multiple detectors are used, for example, to increase thepixel rate of the measurement devices described herein. In response toreceiving the focused backscattered light, the detector 120 generatesone or more sensing signals, which are ultimately used to detect thedistance and/or shapes of objects that reflect the emitted light backtowards the measurement device 100 and ultimately to the detector 120.

FIG. 7 shows a measurement device 200 including a housing 202 with abase member 204 and a transparent cover 206 that can be coupled togetherto surround an internal cavity 208 in which various components of themeasurement device 200 are positioned. For simplicity, the housing 202in FIG. 7 is shown with only the base member 204 and the cover 206, butthe housing 202 can comprise any number of components that can beassembled together to create the internal cavity 208 and securecomponents of the measurement device 200.

The measurement device 200 includes a light source 210 (e.g., a laser;LED), a disk 212 (e.g., a rotatable disk such as the disk shown in FIGS.1-3), a reflecting apparatus 214 (e.g., a rotatable pyramidal-shapedmirror), a focusing apparatus 216 (e.g., a curved mirror such as aparabolic mirror), and a detector 218. The light source 210, the disk212, the reflecting apparatus 214, the detector 218, and othercomponents of the measurement device 200 described below can includeand/or incorporate materials, features, functions, etc., like similarcomponents shown and described with respect to the measurement device100. As such, although the description of the components of themeasurement device 200 below is abbreviated, the components can includefeatures described in more detail with respect to the measurement device100.

The light source 210 can be a laser or a light-emitting diode. Incertain embodiments, the light source 210 emits light within theinfrared spectrum while in other embodiments the light source 210 emitslight within the visible spectrum. In certain embodiments, the lightsource 210 is configured to emit light in pulses. Although only onelight source 210 is shown in FIG. 7, multiple light sources can be usedwith the measurement device 200.

The light emitted by the light source 210 is directed towards the disk212. The emitted light is represented in FIG. 7 by reference number 220.The disk 212 includes at least one set of prisms 222. The measurementdevice 200 can include a motor that rotates the disk 212. As the disk212 rotates, the emitted light 220 is deflected in a cone patternresulting in a circle. The emitted light 220 deflected by the disk 212is then directed towards the rotating mirror 214. The rotating mirror214 is coupled to a motor that rotates the rotating mirror 214 duringoperation of the measurement device 200.

The rotating mirror 214 comprises a plurality of facets/faces thatinclude or otherwise incorporate a reflective surface such as a mirror.The disk 212 and the rotating mirror 214 can be used to create lightpatterns such as the light pattern 136A, 136B shown in FIGS. 6A and 6B.The emitted light 220 is transmitted out of the housing 202 of themeasurement device 200 towards objects. A portion of the emitted lightreflects off the objects and returns through the cover 206. This light,referred to as backscattered light, is represented in FIG. 7 byreference number 224 (not all of the backscattered light is associatedwith a reference number in FIG. 7). The backscattered light 224 isreflected by the rotating mirror 214 through the disk 212 and towardsthe focusing apparatus 216.

FIG. 8 shows a perspective view of an exemplary focusing apparatus 216in the shape of a parabolic mirror. The dotted lines 226 in FIG. 8 showwhere the parabolic mirror could be cut to create the shape of thefocusing apparatus 216 shown in FIG. 7 which is less than the full 360degrees of the parabolic mirror shown in FIG. 8. The focusing apparatus216 can include an aperture 228 to permit the emitted light 220 from thelight source 210 to pass through the focusing apparatus 216 to the disk212.

The backscattered light 224 reflected by the rotating mirror 214 isfocused by the focusing apparatus 216 towards the detector 218. Forexample, when the focusing apparatus 216 is a parabolic mirror, theparabolic mirror and the detector 218 can be positioned with respect toeach other such that the parabolic mirror's focal point is at thedetector 218. The particular shape, size, position, and orientation ofthe focusing apparatus 216 in the measurement device 200 can depend on,among other things, the position of the detector(s) 218, where thepath(s) at which backscattered light 224 is directed within the housing202, and space constraints of the measurement device 200.

The focusing apparatus 216 can focuse backscattered light 224 to one ormore detectors 218, such as photodetectors/sensors. In response toreceiving the focused backscattered light, the detector 218 generatesone or more sensing signals, which are ultimately used to detect thedistance and/or shapes of objects that reflect the emitted light backtowards the measurement device 200 and ultimately to the detector 218.

FIG. 9 shows a measurement device 300 including a housing 302 with abase member 304 and a transparent cover 306 that can be coupled togetherto surround an internal cavity 308 in which various components of themeasurement device 200 are positioned. For simplicity, the housing 302in FIG. 9 is shown with only the base member 304 and the cover 306, butthe housing 302 can comprise any number of components that can beassembled together to create the internal cavity 308 and securecomponents of the measurement device 300.

The measurement device 300 includes a light source 310 (e.g., a laser;LED), a beam splitter 312, a first reflecting apparatus 314 (e.g., astationary mirror), a disk 316 (e.g., a rotatable disk such as the diskshown in FIGS. 1-3), a second reflecting apparatus 318 (e.g., arotatable pyramidal-shaped mirror), a focusing apparatus 320 (e.g., acurved mirror such as a parabolic mirror), a first detector 322A, and asecond detector 322B. The light source 310, the first reflectingapparatus 314, the disk 316, the second reflecting apparatus 318, thefirst detector 322A, the second detector 322B, and other components ofthe measurement device 300 described below can include and/orincorporate materials, features, functions, etc., like similarcomponents shown and described with respect to the measurement devices100 and 200. As such, although the description of the components of themeasurement device 300 below is abbreviated, the components can includefeatures described in more detail with respect to the measurementdevices 100 and 200.

The light source 310 can be a laser or a light-emitting diode. Incertain embodiments, the light source 310 emits light within theinfrared spectrum while in other embodiments the light source 310 emitslight within the visible spectrum. In certain embodiments, the lightsource 310 is configured to emit light in pulses. Although only onelight source 310 is shown in FIG. 9, multiple light sources can be usedwith the measurement device 300.

The light emitted by the light source 310 is directed towards the beamsplitter 312. The emitted light is represented in FIGS. 9 and 10 byreference number 324 for light emitted from the light source 310. Thebeam splitter 312 separates the emitted light 324 into at least twoseparate beams, which are represented separately with reference numbers324A and 324B. In other embodiments, separate beams are created by usingmultiple light sources. In other embodiments, in place of the beamsplitter 312, one or more optical switches can be used. Optical switchescan be used to switch between or among different light paths within themeasurement device 300.

Each beam 324A, 324B is directed towards different portions (e.g.,facets) of the disk 316 via one or more reflecting apparatuses 314 suchas front-surface mirrors. The disk 316 includes at least one set ofprisms 326. The measurement device 300 can include a motor that rotatesthe disk 316. As the disk 316 rotates, each light beam 324A, 324B isdeflected in a separate cone pattern resulting in a circle. The lightbeams 324A, 324B deflected by the disk 316 are then directed towards therotating mirror 318.

The rotating mirror 318 is coupled to a motor that rotates the rotatingmirror 318 during operation of the measurement device 300 and comprisesa plurality of facets/faces 326A-F that include or otherwise incorporatea reflective surface such as a mirror. FIG. 10 shows each light beam324A, 324B being directed towards a different facet 326A-F of therotating mirror 318 at any given point in time. For example, at thepoint in time shown in FIG. 10, the light beam 324A is directed towardsthe facet 326A and the light beam 324B is directed towards another facet326B. Directing emitted light towards multiple facets of the rotatingmirror 318 increases the horizontal components of the total field ofview of the measurement device. When a separate light beam is directedtowards two of the six facets 326A-F of the rotating mirror 318, thehorizontal component is 120 degrees. For a 360-degree horizontal fieldof view, a measurement device could include six separate light beams(via multiple light sources and/or one or more beam splitters) eachreflecting off a separate facet of the rotating mirror 318.

The disk 316 and the rotating mirror 318 can be used to create separatelight patterns such as the light pattern 136A, 136B shown in FIGS. 6Aand 6B. The emitted light 324A, 324B is transmitted out of the housing302 of the measurement device 300 towards objects. A portion of theemitted light reflects off the objects and returns through the cover306. This light, referred to as backscattered light, is represented inFIGS. 9 and 10 by reference number 328 (not all of the backscatteredlight is associated with a reference number in FIGS. 9 and 10). Thebackscattered light 328 is reflected by the rotating mirror 318 throughthe disk 316 and towards the focusing apparatus 320. The focusingapparatus 320 can include an aperture 330 to permit the emitted light324 from the light source 310 to pass through the focusing apparatus 320to the disk 316.

The backscattered light 328 reflected is focused by the focusingapparatus 320 towards the first detector 322A and the second detector322B. In certain embodiments, the measurement device 300 includes one ormore lenses 332A, 332B (e.g., wide-angle lens) between the focusingapparatus 320 and the detectors 322A and 322B. The lenses 332A, 332B cancollect and focus backscattered light 328 from a large angle (e.g., upto 180 degrees) from the focusing apparatus 320. Although only themeasurement device 300 shown in FIGS. 9 and 10 is described asincorporating lenses 332A, 332B, other measurement devices describedherein can utilize such lenses in connection with a parabolic mirror oranother type of focusing apparatus. Further, in other embodiments, themeasurement device 300 does not include the lenses 332A and 332B.

In response to receiving the focused backscattered light, the detectors322A and 322B generate one or more sensing signals, which are ultimatelyused to detect the distance and/or shapes of objects that reflect theemitted light back towards the measurement device 300 and ultimately tothe detectors 322A and 322B. The particular shape, size, position, andorientation of the focusing apparatus 320 in the measurement device 300can depend on, among other things, the position of the detectors 322Aand 322B, where the path(s) at which backscattered light 328 is directedwithin the housing 302, and space constraints of the measurement device300.

FIG. 11 shows a measurement device 400 including a housing 402 with abase member 404 and a transparent cover 406 that can be coupled togetherto surround an internal cavity 408 in which various components of themeasurement device 400 are positioned. For simplicity, the housing 402in FIG. 11 is shown with only the base member 404 and the cover 406, butthe housing 402 can comprise any number of components that can beassembled together to create the internal cavity 408 and securecomponents of the measurement device 400.

The measurement device 400 includes multiple light sources 410A-C (e.g.,lasers; LEDs), a disk 412 (e.g., a rotatable disk such as the disk shownin FIGS. 1-3), a reflecting apparatus 414 (e.g., a rotatablepyramidal-shaped mirror), a focusing apparatus 416 (e.g., a curvedmirror such as a parabolic mirror), and multiple detectors 418A-C. Thelight sources 410A-C, the disk 412, the reflecting apparatus 414, thedetectors 418A-C, and other components of the measurement device 400described below can include and/or incorporate materials, features,functions, etc., like similar components shown and described withrespect to the measurement devices 100, 200, and 300. As such, althoughthe description of the components of the measurement device 400 below isabbreviated, the components can include features described in moredetail with respect to the measurement devices 100, 200, and 300.

Each of the light sources 410A-C can be a laser or a light-emittingdiode. Although multiple light sources 410A-C are shown in FIG. 11, asfew as one light source (along with one or more beam splitters and/oroptical switches) can be used to accomplish similar or equivalentfunctions. In certain embodiments, the light sources 410A-C emit lightwithin the infrared spectrum while in other embodiments the lightsources 410A-C emit light within the visible spectrum. In certainembodiments, the light sources 410A-C are configured to emit light inpulses. In embodiments with multiple light sources, the light sourcescan fire asynchronous. The asynchronous timing can avoid interference ofbackscattered light at the detector(s) from different light sources.

The light emitted by the light sources 410A-C is directed towardsdifferent portions of the disk 412, which steers the emitted lighttowards different facets of the rotating mirror 414. The emitted lightis represented in FIG. 11 by reference numbers 420A-C. The disk 412includes at least one set of prisms 422. The measurement device 400 caninclude a motor that rotates the disk 412. As the disk 412 rotates, eachbeam 420A-C of the the emitted light is deflected in a separate conepattern resulting in a separate circle. The emitted light 420A-Cdeflected by the disk 412 is then directed towards the rotating mirror414. The rotating mirror 414 is coupled to a motor that rotates therotating mirror 414 during operation of the measurement device 100.

The rotating mirror 414 comprises a plurality of facets/faces thatinclude or otherwise incorporate a reflective surface such as a mirror.The disk 412 and the rotating mirror 414 can be used to create lightpatterns such as the light pattern 136A, 136B shown in FIGS. 6A and 6B.When the light patterns generated from each of the light sources 410A-Care combined, the measurement device's 400 total field of view 424 isapproximately the shape shown in FIG. 12 with a horizontal componentlarger than if only a single light path were used.

The emitted light 420 is transmitted out of the housing 402 of themeasurement device 400 towards objects. A portion of the emitted lightreflects off the objects and returns through the cover 406. This light,referred to as backscattered light, is represented in FIG. 11 bymultiple arrows 426 (not all of the backscattered light is associatedwith a reference number in FIG. 11). The backscattered light 426 isreflected by the rotating mirror 414 through the disk 412 and towardsthe focusing apparatus 416.

The reflected backscattered light 426 is focused by the focusingapparatus 416 towards the detectors 418A-C. For example, when thefocusing apparatus 416 is a parabolic mirror, the parabolic mirror andthe detectors 418A-C can be positioned with respect to each other suchthat the parabolic mirror's focal point is at the detectors 418A-C. Theparticular shape, size, position, and orientation of the focusingapparatus 416 in the measurement device 400 can depend on, among otherthings, the position of the detector(s) 418A-C, where the path(s) atwhich backscattered light 426 is directed within the housing 402, andspace constraints of the measurement device 400. In response toreceiving the focused backscattered light, the detectors 418A-C generateone or more sensing signals, which are ultimately used to detect thedistance and/or shapes of objects that reflect the emitted light backtowards the measurement device 400 and ultimately to the detectors418A-C.

FIG. 13 shows a measurement device 500 including a housing 502 with abase member 504 and a transparent cover 506 that can be coupled togetherto surround an internal cavity 508 in which various components of themeasurement device 500 are positioned. For simplicity, the housing 502in FIG. 13 is shown with only the base member 504 and the cover 506, butthe housing 502 can comprise any number of components that can beassembled together to create the internal cavity 508 and securecomponents of the measurement device 500.

The measurement device 500 includes a light source 510, a beam steeringdevice 512 (e.g., a rotating mirror such as a micro electro mechanicalsystems (MEMS)-based mirror or electro-optical devices such as apotassium tantalate niobite crystal or lithium niobite crystal), a disk514 (e.g., a rotatable disk such as the disk shown in FIGS. 1-3), areflecting apparatus 516 (e.g., a rotatable pyramidal-shaped mirror), afocusing apparatus 518 (e.g., a curved mirror such as a parabolicmirror), and a detector 520. The light source 510, the disk 514, thereflecting apparatus 516, the focusing apparatus 518, the detector 520,and other components of the measurement device 500 described below caninclude and/or incorporate materials, features, functions, etc., likesimilar components shown and described with respect to the measurementdevices 100, 200, 300, and 400. As such, although the description of thecomponents of the measurement device 500 below is abbreviated, thecomponents can include features described in more detail with respect tothe measurement devices 100, 200, 300, and 400.

The light source 510 can be a laser or a light-emitting. In certainembodiments, the light source 510 emits light within the infraredspectrum while in other embodiments the light source 510 emits lightwithin the visible spectrum. In certain embodiments, the light source510 is configured to emit light in pulses. Although only one lightsource 510 is shown in FIG. 13, multiple light sources can be used withthe measurement device 500. The emitted light is represented in FIG. 13by reference number 522.

The emitted light 522 is directed towards the beam steering device 512.One example of a beem steering device is a MEMS-based mirror, which canbe silicon-based and is sometimes referred to as a mirror-on-a-chip. Thebeam steering device 512 can rotate around an axis such that the emittedlight is scanned back and forth along a line. Put another way, the beamsteering device 512 can be used to steer the emitted light 522 along aline and towards the disk 514. This line, when reflected by the rotatingmirror 516, generates a scan pattern with scan lines shaped like thescan lines 524 shown in FIG. 14. In certain embodiments, the scan lines524 can be shaped to have substantially the same amplitude such that thescan lines 524 are similarly shaped. In other embodiments, the amplitudeof the scan lines 524 is modulated such that the peaks and valleys ofthe scan lines 524 are different from line to line and/or along arespective scan line.

As shown in FIG. 13, the beam steering device 512 is angled at a nominalangle of 45 degrees with respect to the emitted light 522 from the lightsource 510 such that the emitted light 522 is reflected at a nominalangle of 90 degrees, although other angles can be used. In certainembodiments, the beam steering device 512 is configured to rotate aroundthe axis within ranges such as 0.10-1 degrees, 0.2-0.5 degrees, and0.29-0.31 degrees, which are small enough to permit as few as onedetector to be used. Using a 0.30-degree range of rotation as anexample, the emitted light 522 would be reflected back and forth betweenangles of 89.7 degrees and 90.3 degrees as the beam steering device 512rotates back and forth within its range of rotation.

The light emitted by the light source 522 and reflected by the beamsteering device 512 is directed towards the disk 514. The disk 514includes at least one set of prisms 526. The measurement device 500 caninclude a motor that rotates the disk 514. As the disk 514 rotates, theemitted light 522 is deflected in a cone pattern resulting in a circle.Because of the use of the beam steering device 512, the circle has a“rougher” circumference (e.g., the scan lines tracing the circumferenceof the circle are shaped like the scan lines 524 shown in FIG. 14). Theemitted light 522 deflected by the disk 514 is then directed towards therotating mirror 516. The rotating mirror 516 is coupled to a motor thatrotates the rotating mirror 516 during operation of the measurementdevice 500.

The rotating mirror 516 comprises a plurality of facets/faces thatinclude or otherwise incorporate a reflective surface such as a mirror.The disk 514 and the rotating mirror 516 can be used to create lightpatterns such as the light pattern 136A, 136B shown in FIGS. 6 and 7where the individual scan lines are shaped like those in FIG. 14. Theemitted light 522 is transmitted out of the housing 502 of themeasurement device 500 towards objects. A portion of the emitted lightreflects off the objects and returns through the cover 506. This light,referred to as backscattered light, is represented in FIG. 13 byreference number 528 (not all of the backscattered light is associatedwith a reference number in FIG. 13). The backscattered light 528 isreflected by the rotating mirror 516 through the disk 514 and towardsthe focusing apparatus 518.

The reflected backscattered light 528 is focused by the focusingapparatus 518 towards the detector 520. For example, when the focusingapparatus 518 is a parabolic mirror, the parabolic mirror and thedetector 520 can be positioned with respect to each other such that themirror's focal point is at the detector 520. The particular shape, size,position, and orientation of the focusing apparatus 518 in themeasurement device 500 can depend on, among other things, the positionof the detector(s) 520, where the path(s) at which backscattered light528 is directed within the housing 502, and space constraints of themeasurement device 500.

The focusing apparatus 518 can focus the backscattered light 528 to oneor more detectors 520, such as photodetectors/sensors. In response toreceiving the focused backscattered light, the detector 520 generatesone or more sensing signals, which are ultimately used to detect thedistance and/or shapes of objects that reflect the emitted light backtowards the measurement device 500 and ultimately to the detector 520.

FIG. 15 shows a measurement device 600 including a housing 602 with abase member 604 and a transparent cover 606 that can be coupled togetherto surround an internal cavity 608 in which various components of themeasurement device 600 are positioned. For simplicity, the housing 602in FIG. 15 is shown with only the base member 604 and the cover 606, butthe housing 602 can comprise any number of components that can beassembled together to create the internal cavity 608 and securecomponents of the measurement device 600. FIG. 16 shows a top view ofcertain components of the measurement device 600.

The measurement device 600 includes multiple light sources 610A-F (e.g.,lasers; LEDs), a disk 612 (e.g., a rotatable disk such as the disk shownin FIGS. 1-3), a reflecting apparatus 614 (e.g., a rotatablepyramidal-shaped mirror), a focusing apparatus 616 (e.g., a curvedmirror such as a parabolic mirror), and multiple detectors 618A and618B. The light sources 610A-F, the disk 612, the reflecting apparatus614, the detectors 618A and 618B, and other components of themeasurement device 600 described below can include and/or incorporatematerials, features, functions, etc., like similar components shown anddescribed with respect to the measurement devices 100, 200, 300, 400,and 500. As such, although the description of the components of themeasurement device 600 below is abbreviated, the components can includefeatures described in more detail with respect to the measurementdevices 100, 200, 300, 400, and 500.

The light sources 610A-F can be lasers or light-emitting diodes.Although multiple light sources 610A-F are shown in FIG. 15, as few asone light source (along with one or more beam splitters and/or opticalswitches) can be used to accomplish similar or equivalent functions. Incertain embodiments, the light sources 610A-F emit light within theinfrared spectrum while in other embodiments the light sources 610A-Femit light within the visible spectrum. In certain embodiments, thelight sources 610A-F are configured to emit light in pulses. The emittedlight is represented in FIGS. 15 and 16 by reference numbers 620A-F ofwhich only 620A and 620B are shown in FIG. 15.

FIG. 15 shows two of the light sources 610A and 610B arranged such thelight emitted 620A, 620B by the respective light sources 610A and 610Bare offset. The offset is represented in FIG. 15 by an “X” and shown asbeing approximately a 10-degree offset, although other offsets (e.g.,5-15 degrees, 5-25 degrees) can be used depending on the desired totalfield of view, prism angles, etc. FIG. 16 shows the light sources 610Aand 610B arranged to direct emitted light 620A, 620B towards the samefacet (at a given point in time) of the rotating mirror 614. The otherpairs of light sources (i.e., 610C and 610D; 610E and 610F) are alsooffset from each other, and each pair is arranged such that emittedlight 620C-F is directed towards respective facets of the rotatingmirror 614 at a given point in time.

The light emitted 620A-F by the light sources 610A-F is directed towardsthe disk 612. The disk 612 includes at least one set of prisms 622. Themeasurement device 600 can include a motor that rotates the disk 612. Asthe disk 612 rotates, the emitted light 620A-F is deflected in separatecone patterns resulting in separate circles. The emitted light 620A-Fdeflected by the disk 612 is then directed towards the rotating mirror614. The rotating mirror 614 is coupled to a motor that rotates therotating mirror 614 during operation of the measurement device 600.

The rotating mirror 614 comprises a plurality of facets/faces 624A-Ithat include or otherwise incorporate a reflective surface such as amirror. In FIG. 16, the rotating mirror is shown as including ninefacets 624A-I. The disk 612 and the rotating mirror 614 can be used tocreate light patterns such as the light pattern 136A, 136B shown inFIGS. 6 and 7. The emitted light 620A-F is transmitted out of thehousing 602 of the measurement device 600 towards objects. A portion ofthe emitted light reflects off the objects and returns through the cover606. This light, referred to as backscattered light, is represented inFIGS. 15 and 16 by reference number 626 (not all of the backscatteredlight is associated with a reference number in FIGS. 15 and 16). Thebackscattered light 626 is reflected by the rotating mirror 614 throughthe disk 612 and towards the focusing apparatus 616.

The backscattered light 626 reflected is focused by the focusingapparatus 616 towards the detectors 618A and 618B. For example, when thefocusing apparatus 616 is a parabolic mirror, the parabolic mirror andthe detectors 618A and 618B can be positioned with respect to each othersuch that the parabolic mirror's focal point is at the detectors 618Aand 618B. The particular shape, size, position, and orientation of thefocusing apparatus 616 in the measurement device 600 can depend on,among other things, the position of the detectors 618A and 618B, wherethe path(s) at which backscattered light 626 is directed within thehousing 602, and space constraints of the measurement device 600. Inresponse to receiving the focused backscattered light, the detectors618A and 618B generate one or more sensing signals, which are ultimatelyused to detect the distance and/or shapes of objects that reflect theemitted light back towards the measurement device 600 and ultimately tothe detectors 618A and 618B.

FIG. 17 shows a top view of a disk 650 that could be used in themeasurement devices 100, 200, 300, 400, 500, and 600 described above inplace of the disks described above. The disk 650 includes a plurality ofsets 652A-C of respective prisms 654A-C. Each set 652A-C includes prisms654A-C with prism angles that are different from the prism angles ofprisms 654A-C in the other sets 652A-C. As such, the disk 650 can bedesigned to have a different resolution at particular portions of thetotal field of view. For example, the prisms 654A in the inner set 652Acan have the highest prism angle (e.g., 8-10 degrees), the prisms 654Bin the middle set 652B can have a lower prism angle than those in theinner set 652A (e.g., 5-8 degrees), and the prisms 654C in the outer set652C can have the lowest prism angle (e.g., 1-5 degrees) than those inthe other sets 652A and 652B. Light passing through lower prism angleswill be steered along a smaller diameter circle compared to the angularresolution of higher prism angles in a given amount of time. As such, ifthe laser fire rate through each set of prisms is held constant, thelower prism angles will have a higher angular resolution compared tohigher prism angles. Using the above-described sets, the inner set 652Aof prisms 654A with the highest prism angle may be most useful fordetecting nearby objects, the midde set 652B of prisms 654B with thelower prism angle may be most useful for detecting between nearbyobjects and faraway objects, while the outer set 652C of prisms 654Cwith the lowest prism angle may be most useful for detecting farawayobjects.

In measurement devices using a disk sectioned with prisms with differentprism angles (e.g., the disk 650), the measurement devices can include anumber of lights beams/paths (either generated via multiple lightsources or with one or more beam splitters) and a number of detectorsequal or greater to the number of different prism sections on the disk.Each different section of the disk would be associated with at least onelight beam/path.

FIG. 18 shows a measurement device 700 including a housing 702 with abase member 704 and a transparent cover 706 that can be coupled togetherto surround an internal cavity 708 in which various components of themeasurement device 700 are positioned. For simplicity, the housing 702in FIG. 18 is shown with only the base member 704 and the cover 706, butthe housing 702 can comprise any number of components that can beassembled together to create the internal cavity 708 and securecomponents of the measurement device 700.

The measurement device 700 includes a light source 710, a first disk712A (e.g., a rotatable disk such as the disk shown in FIGS. 1-3), asecond disk 712B (e.g., a rotatable disk such as the disk shown in FIG.19), a reflecting apparatus 714 (e.g., a stationary conical-shapedmirror), a focusing apparatus 716 (e.g., a curved mirror such as aparabolic mirror), and a detector 718. The light source 710, the firstdisk 712A, the reflecting apparatus 714, the detector 718, and othercomponents of the measurement device 700 described below can includeand/or incorporate materials, features, functions, etc., like similarcomponents shown and described with respect to the measurement devices100, 200, 300, 400, 500, and 600. As such, although the description ofthe components of the measurement device 700 below is abbreviated, thecomponents can include features described in more detail with respect tothe measurement devices 100, 200, 300, 400, 500, and 600.

The light source 710 can be a laser or a light-emitting diode. Incertain embodiments, the light source 710 emits light within theinfrared spectrum while in other embodiments the light source 710 emitslight within the visible spectrum. In certain embodiments, the lightsource 710 is configured to emit light in pulses. Although only onelight source 710 is shown in FIG. 18, multiple light sources and/or oneor more beam splitters or optical switches can be used with themeasurement device 700 to generate multiple light beams. The emittedlight is represented in FIG. 18 by reference number 720.

The first disk 712A and the second disk 712B can be configured to rotateindependently of each other in the same or opposite direction and/or atthe same or different speed. Each disk can be driven to rotate by adedicated motor. For example, the motors can be coaxial and coupleddirectly or indirectly to a central portion or outer circumference ofthe respective disks.

The first disk 712A includes at least one set of prisms 722 similar tothe disks described above. The second disk 712B is shown in FIG. 19 asincluding multiple sets of prisms 724A-F. Each set of prisms 724A-F canextend in different directions than each other. For example, the sets ofprisms 724A-F are shown in FIG. 19 as extending radially outward betweenan inner portion 726 and an outer circumference 728 of the second disk712B in six different sections. Each set of prisms 724A-F can be angledat the same or different prism angle as the other prisms. When theemitted light 720 passes through the second disk 712B, the emitted light720 is steered onto the reflecting apparatus 714. In certainembodiments, the reflecting apparatus 714 is a stationary conical-shapedmirror, which diverges the emitted light 720 from the second disk 712Binto a collimated beam. As the second disk 712B rotates and changes itsangular position, the emitted light 720 is scanned back and forth acrossthe field of view.

The emitted light 720 is transmitted out of the housing 702 of themeasurement device 700 towards objects. A portion of the emitted lightreflects off the objects and returns through the cover 706. This light,referred to as backscattered light, is represented in FIG. 18 byreference number 730 (not all of the backscattered light is associatedwith a reference number in FIG. 18). The backscattered light 730 isreflected by the reflecting apparatus 714 through the second disk 712Band then the first disk 712A towards the focusing apparatus 716.

The backscattered light 730 reflected by the reflecting apparatus 714 isfocused by the focusing apparatus 716 towards the detector 718. Forexample, when the focusing apparatus 716 is a parabolic mirror, theparabolic mirror and the detector 718 can be positioned with respect toeach other such that the parabolic mirror's focal point is at thedetector 718. The particular shape, size, position, and orientation ofthe focusing apparatus 716 in the measurement device 700 can depend on,among other things, the position of the detector(s) 718, where thepath(s) at which backscattered light 730 is directed within the housing702, and space constraints of the measurement device 700.

The focusing apparatus 716 can focus the backscattered light 730 to oneor more single detectors 718, such as photodetectors/sensors. Inresponse to receiving the focused backscattered light, the detector 718generates one or more sensing signals, which are ultimately used todetect the distance and/or shapes of objects that reflect the emittedlight back towards the measurement device 700 and ultimately to thedetector 718.

FIG. 20 shows a measurement device 800 including a housing 802 with abase member 804 and a transparent cover 806 that can be coupled togetherto surround an internal cavity 808 in which various components of themeasurement device 800 are positioned. For simplicity, the housing 802in FIG. 20 is shown with only the base member 804 and the cover 806, butthe housing 802 can comprise any number of components that can beassembled together to create the internal cavity 808 and securecomponents of the measurement device 800.

The measurement device 800 includes a light source 810, a beam splitter811, a first disk 812A (e.g., a rotatable disk such as the disk shown inFIGS. 1-3), a second disk 812B (e.g., a rotatable disk such as the diskshown in FIG. 21), a first reflecting apparatus 814 (e.g., a rotatablepyramidal-shaped mirror), a focusing apparatus 816 (e.g., a lens), asecond reflecting apparatus 818 (e.g., a stationary mirror), a firstdetector 820A (e.g., a sensor), and a second detector 820B (e.g., asensor). The various components of the measurement device 800 describedbelow can include and/or incorporate materials, features, functions,etc., like similar components shown and described with respect to themeasurement devices 100, 200, 300, 400, 500, 600, and 700. As such,although the description of the components of the measurement device 800below is abbreviated, the components can include features described inmore detail with respect to the measurement devices 100, 200, 300, 400,500, 600, and 700.

The light source 810 can be a laser or a light-emitting diode. Incertain embodiments, the light source 810 emits light within theinfrared spectrum while in other embodiments the light source 810 emitslight within the visible spectrum. In certain embodiments, the lightsource 810 is configured to emit light in pulses. Although only onelight source 810 is shown in FIG. 20, multiple light sources can be usedwith the measurement device 800 to generate multiple light beams. Thelight emitted by the light source 810 is directed towards the beamsplitter 811. The emitted light is represented in FIG. 20 by referencenumbers 822A and 822B for light emitted from the light source 810 andseparated into two beams by the beam splitter 811.

The first disk 812A and the second disk 812B can be configured to rotateindependently of each other in the same or opposite direction and/or atthe same or different speed. Each disk can be driven to rotate by adedicated motor. For example, the motors can be coaxial and coupleddirectly or indirectly to a central portion or outer circumference ofthe respective disks. As shown in FIG. 20, in certain embodiments, thesecond disk 812B is directly coupled to the rotating mirror 814. Assuch, the second disk 812B and the rotating mirror 814 rotate together.In other embodiments, the second disk 812B is not directly coupled tothe rotating mirror 814 and instead is positioned elsewhere within theemitted light's optical path. For example, the particular arrangement ofthe first disk 812A with respect to the second disk 812B can be modifiedfrom the arrangement shown in FIG. 20 without modifying the overallfunction of the second disk 812B. For example, the second disk 812B canrotate around an axis that is perpendicular to the rotational axis ofthe first disk 812A.

The first disk 812A includes at least one set of prisms 824 similar tothe disks described above. The second disk 812B is shown in FIG. 21 asincluding multiple sets of prisms 826A-F and an optional planar portion828 (e.g., a prism-less portion of the second disk 812B). Each set ofprisms 826A-F can extend in different directions than each other. Forexample, the sets of prisms 826A-F are shown in FIG. 21 as extendingradially outward to outer circumference 830 of the second disk 812B insix different sections. Each set of prisms 826A-F can be angled at thesame or different prism angle as the other sets of prisms. As onenon-limiting example, three sets of prisms (e.g., 826A, 826C, and 826E)can be angled at 10 degrees while the three other sets of prisms (e.g.,826B, 826D, and 826F) can be angled at 12 degrees. As such, in this oneexample, the sets of prisms 826A-F alternate between two differentangles. Alternatively or additionally, as described above, the facets ofthe rotating mirror 814 can be angled at different angles for a similareffect.

When the emitted light 822A and 822B passes through the second disk812B, the emitted light 822A and 822B is steered onto the rotatingmirror 814. The rotating mirror 814 comprises a plurality offacets/faces 832A-F that include or otherwise incorporate a reflectivesurface such as a mirror. In certain embodiments, the number ofdifferent sets of prisms 826A-F are the same number of facets 832A-F onthe rotating mirror 814.

One concern with using a single light source 810 is that the emittedlight when split (e.g., via a beam splitter) is scanned across twofacets at the same point in time and is then collected across an areathat is shared between two facets as the rotating mirror 814 rotates.For example, for a six-faceted rotating mirror 814, two adjacent facetswill occupy up to 60 degrees of the same collection area at a givenpoint in time. As such, unless accounted for using techniques such aswavelength separation or multiple light beams, the two facets will sharea single detector.

One approach to address this concern is to incorporate the second disk812B as shown in FIG. 21. The second disk 812B includes the planarportion 828, which helps keep the paths of the emitted light 822A and822B from deviating. Further, the sets of prisms 826A-F are angled in analternative fashion, which separates the backscattered light paths fromtwo different facets. In such an arrangement, the second disk 8128should be phase-locked to the rotating mirror 814 (e.g., viamechanically fixing the second disk 812B to the rotating mirror 814, viausing a separate motor to rotate the second disk 812B that isphase-locked to the motor rotating the rotating mirror 814). Thealternating prism angles of the sets of prisms 826A-F will separatebackscattered light for two facets of the rotating mirror 814. As such,when the emitted light 822A and 822B from a single light source 810 issplit into separate paths and sent to two different facets, thebackscattered light can be disambiguated through the use of two separatedetectors 820A and 820B.

The emitted light 822A and 822B is transmitted out of the housing 802 ofthe measurement device 800 towards objects. A portion of the emittedlight reflects off the objects and returns through the cover 806. Thislight, referred to as backscattered light, is represented in FIG. 20 byreference number 832 (not all of the backscattered light is associatedwith a reference number in FIG. 20). The backscattered light 832 isreflected by the rotating mirror 814 through the second disk 812B, thenthe first disk 812A, and then the focusing apparatus 816 towards thestationary mirror 818. As shown in FIG. 20, both the focusing apparatus816 and the stationary mirror 818 includes apertures 834A, 834B throughwhich the emitted light 822A and 822B can pass towards the first disk812A.

The backscattered light 832 reflected by the stationary mirror 818 isreflected towards the detectors 820A and 820B. The particular shape,size, position, and orientation of the focusing apparatus 816 and thestationary mirror 818 in the measurement device 800 can depend on, amongother things, the position of the detector(s) 820A and 820B, where thepath(s) at which backscattered light 832 is directed within the housing802, and space constraints of the measurement device 800.

In response to receiving the backscattered light 832, the detectors 820Aand 820B generate one or more sensing signals, which are ultimately usedto detect the distance and/or shapes of objects that reflect the emittedlight back towards the measurement device 800 and ultimately to thedetectors 820A and 820B.

FIGS. 22A and 22B show a measurement device 900 with two alternativearrangements of the various optical elements of the measurement device900. These Figures show that the optical elements shown and describedabove can have different physical arrangements than the arrangementsspecifically shown in the Figures.

The measurement device 900 includes a housing 902 with a base member 904and a transparent cover 906 that can be coupled together to surround aninternal cavity 908 in which various components of the measurementdevice 900 are positioned. For simplicity, the housing 902 in FIGS. 22Aand 22B is shown with only the base member 904 and the cover 906, butthe housing 902 can comprise any number of components that can beassembled together to create the internal cavity 908 and securecomponents of the measurement device 900.

The measurement device 900 includes a light source 910, a disk 912(e.g., a rotatable disk such as the disk shown in FIGS. 1-3), a firstreflecting apparatus 914 (e.g., a rotatable pyramidal-shaped mirror), asecond reflecting apparatus 916 (e.g., a stationary mirror), a focusingapparatus 918 (e.g., a lens; a curved mirror such as a parabolicmirror), and a detector 920 (e.g., a sensor). The components of themeasurement device 900 described below can include and/or incorporatematerials, features, functions, etc., like similar components shown anddescribed with respect to the measurement devices 100, 200, 300, 400,500, 600, 700, and 800. As such, although the description of thecomponents of the measurement device 900 below is abbreviated, thecomponents can include features described in more detail with respect tothe measurement devices 100, 200, 300, 400, 500, 600, 700, and 800.

The light source 910 can be a laser or a light-emitting diode. Incertain embodiments, the light source 910 emits light within theinfrared spectrum while in other embodiments the light source 910 emitslight within the visible spectrum. In certain embodiments, the lightsource 910 is configured to emit light in pulses. Although only onelight source 910 is shown in FIGS. 22A and 22B, multiple light sourcescan be used with the measurement device 900 to generate multiple lightbeams/paths. Further, multiple light beams/paths can be created usingbeam splitters and/or optical switches. The emitted light is representedin FIGS. 22A and 22B by reference number 922.

As shown in FIGS. 22A and 22B, the light source 910 can have differentpositions and orientations within the measurement device. In FIG. 22A,the light source 910 is positioned and oriented such that the emittedlight 922 is directed towards the disk 912 parallel to an axis ofrotation of the disk 912 and without any type of reflector positionedwithin the optical path between the light source 910 and the disk 912.In FIG. 22B, the light source 910 is positioned and oriented such thatthe emitted light 922 is initially directed perpendicular to the theaxis of rotation of the disk 912 and with the stationary mirror 916positioned in the optical path between the light source 910 and the disk912. The stationary mirror 916 in FIG. 22B relfects the emitted light922 towards the disk 912.

The stationary mirror 916 can be a front surface mirror that is angledand positioned to reflect the emitted light 922 (in the arrangement inFIG. 22B) and backscattered light in the arrangements of FIGS. 22A and22B. Although the stationary mirror 916 is shown as having an angle ofapproximately 45 degrees, other angles can be used. The stationarymirror 916 can include an aperture to permit the emitted light 922 fromthe light source 910 to pass through the stationary mirror 916 in thearrangement of FIG. 22A.

The disk 912 includes at least one set of prisms 924. The measurementdevice 900 can include a motor that rotates the disk 912. As the disk912 rotates, the emitted light 922 is deflected in a cone patternresulting in a circle. The emitted light 922 deflected by the disk 912is then directed towards the rotating mirror 914. The rotating mirror914 is coupled to a motor that rotates the rotating mirror 914 duringoperation of the measurement device 900.

The rotating mirror 914 comprises a plurality of facets/faces thatinclude or otherwise incorporate a reflective surface such as a mirror.The disk 912 and the rotating mirror 914 can be used to create lightpatterns such as the light pattern 136A, 136B shown in FIGS. 6A and 6B.The emitted light 922 is transmitted out of the housing 902 of themeasurement device 900 towards objects. A portion of the emitted lightreflects off the objects and returns through the cover 906. This light,referred to as backscattered light, is represented in FIGS. 22A and 22Bby reference number 926 (not all of the backscattered light isassociated with a reference number in FIGS. 22A and 22B). Thebackscattered light 926 is reflected by the rotating mirror 914 and thenpasses through the disk 912 and towards the focusing apparatus 918.

The focusing apparatus 918 is an optical element such as a lens thatfocuses the backscattered light 926 towards the stationary mirror 916and ultimately to the detector 920. The focused backscattered light 926is reflected by the stationary mirror 916 towards the detector 920. Theparticular shape, size, position, and orientation of the focusingapparatus 918 in the measurement device 900 can depend on, among otherthings, the position of the detector(s) 920, where the path(s) at whichbackscattered light 926 is directed within the housing 902, and spaceconstraints of the measurement device 900. In both arrangements of FIGS.22A and 22B, the focusing apparatus 918 includes an aperture to allowthe emitted light 922 to pass through the focusing apparatus 918 towardsthe disk 912.

In response to receiving the focused backscattered light, the detector920 generates one or more sensing signals, which are ultimately used todetect the distance and/or shapes of objects that reflect the emittedlight back towards the measurement device 900 and ultimately to thedetector 920.

FIG. 23 shows a measurement device 1000 including a housing 1002 with abase member 1004 and a transparent cover 1006 that can be coupledtogether to surround an internal cavity 1008 in which various componentsof the measurement device 1000 are positioned. For simplicity, thehousing 1002 in FIG. 23 is shown with only the base member 1004 and thecover 1006, but the housing 1002 can comprise any number of componentsthat can be assembled together to create the internal cavity 1008 andsecure components of the measurement device 1000.

The measurement device 1000 includes a light source 1010, a disk 1012(e.g., a rotatable disk such as the disk shown in FIGS. 1-3), areflecting apparatus 1014 (e.g., a rotatable pyramidal-shaped mirror), afocusing apparatus 1016 (e.g., a lens; a curved mirror such as aparabolic mirror), and a detector 1018 (e.g., a sensor). The componentsof the measurement device 1000 described below can include and/orincorporate materials, features, functions, etc., like similarcomponents shown and described with respect to the measurement devices100, 200, 300, 400, 500, 600, 700, 800, and 900. As such, although thedescription of the components of the measurement device 1000 below isabbreviated, the components can include features described in moredetail with respect to the measurement devices 100, 200, 300, 400, 500,600, 700, 800, and 900.

The light source 1010 can be a laser or a light-emitting diode. Incertain embodiments, the light source 1010 emits light within theinfrared spectrum while in other embodiments the light source 1010 emitslight within the visible spectrum. In certain embodiments, the lightsource 1010 is configured to emit light in pulses. Although only onelight source 1010 is shown in FIG. 23, multiple light sources can beused with the measurement device 1000 to generate multiple light beams.Further, multiple light beams/paths can be created using beam splittersand/or optical switches. The emitted light is represented in FIG. 23 byreference number 1020. The light source 1010 is positioned and orientedsuch that the emitted light 1020 is directed towards the disk 1012parallel to an axis of rotation of the disk 1012 and without any type ofreflector between the light source 1010 and the disk 1012.

The disk 1012 includes at least one set of prisms 1022. The measurementdevice 1000 can include a motor that rotates the disk 1012. As the disk1012 rotates, the emitted light 1020 is deflected in a cone patternresulting in a circle. The emitted light 1020 deflected by the disk 1012is then directed towards the rotating mirror 1014. The rotating mirror1014 is coupled to a motor that rotates the rotating mirror 1014 duringoperation of the measurement device 1000.

The rotating mirror 1014 comprises a plurality of facets/faces thatinclude or otherwise incorporate a reflective surface such as a mirror.The disk 1012 and the rotating mirror 1014 can be used to create lightpatterns such as the light pattern 136A, 136B shown in FIGS. 6A and 6B.The emitted light 1020 is transmitted out of the housing 1002 of themeasurement device 1000 towards objects. A portion of the emitted lightreflects off the objects and returns through the cover 1006. This light,referred to as backscattered light, is represented in FIG. 23 byreference number 1024 (not all of the backscattered light is associatedwith a reference number in FIG. 23). The backscattered light 1024 isreflected by the rotating mirror 1014 through the disk 1012 and towardsthe focusing apparatus 1016.

The focusing apparatus 1016 is an optical element such as a lens thatfocuses the backscattered light 1024 towards the detector 1018. Theparticular shape, size, position, and orientation of the focusingapparatus 1016 in the measurement device 1000 can depend on, among otherthings, the position of the detector(s) 1018, where the path(s) at whichbackscattered light 1024 is directed within the housing 1002, and spaceconstraints of the measurement device 1000. The focusing apparatus 1016includes an aperture to allow the emitted light 1020 to pass through thefocusing apparatus 1016 towards the disk 1012.

In response to receiving the focused backscattered light, the detector1020 generates one or more sensing signals, which are ultimately used todetect the distance and/or shapes of objects that reflect the emittedlight back towards the measurement device 1000 and ultimately to thedetector 1018. As shown in FIG. 23, the detector 1020 is oriented alongor parallel to the axis of rotation of the rotating mirror 1014.Further, the focusing apparatus 1016 is shown as being larger comparedto lenses shown in other measurement devices.

FIG. 24 shows a measurement device 1100 includes a housing 1102 with abase member 1104 and a transparent cover 1106 that can be coupledtogether to surround an internal cavity 1108 in which various componentsof the measurement device 1100 are positioned. For simplicity, thehousing 1102 in FIG. 24 is shown with only the base member 1104 and thecover 1106, but the housing 1102 can comprise any number of componentsthat can be assembled together to create the internal cavity 1108 andsecure components of the measurement device 1100.

The measurement device 1100 includes multiple light sources 1110A and11108, a disk 112 (e.g., a rotatable disk such as the disk shown inFIGS. 1-3), a first reflecting apparatus 1114 (e.g., a rotatablepyramidal-shaped mirror), a second reflecting apparatus 1116 (e.g., astationary mirror), a focusing apparatus 1118 (e.g., a lens; a curvedmirror such as a parabolic mirror), and a detector 1120 (e.g., asensor). The components of the measurement device 1100 described belowcan include and/or incorporate materials, features, functions, etc.,like similar components shown and described with respect to themeasurement devices 100, 200, 300, 400, 500, 600, 700, 800, 900, and1000. As such, although the description of the components of themeasurement device 1100 below is abbreviated, the components can includefeatures described in more detail with respect to the measurementdevices 100, 200, 300, 400, 500, 600, 700, 800, 900, and 1000.

The light sources 1110A and 11108 can be lasers or light-emittingdiodes. In certain embodiments, the light sources 1110A and 11108 emitlight within the infrared spectrum while in other embodiments the lightsources 1110A and 11108 emit light within the visible spectrum. Incertain embodiments, the light sources 1110A and 11108 are configured toemit light in pulses. The emitted light is represented in FIG. 24 byreference numbers 1122A and 11228. In certain embodiments, the lightsources 1110A and 11108 are oriented such that the emitted light 1122Aand 1122B is directed in non-parallel directions towards the stationarymirror 1116. The stationary mirror 1116 relfects the emitted light 1122Aand 1122B towards the disk 1112. Although the stationary mirror 1116 isshown as having an angle of approximately 45 degrees, other angles canbe used.

The disk 1112 includes at least one set of prisms 1124. The measurementdevice 1100 can include a motor that rotates the disk 1112. As the disk1112 rotates, the emitted light 1122A and 1122B is deflected in separatecone patterns resulting in separate circles. The emitted light 1122A and1122B deflected by the disk 1112 is then directed towards the rotatingmirror 1114. The rotating mirror 1114 is coupled to a motor that rotatesthe rotating mirror 1114 during operation of the measurement device1100.

The rotating mirror 1114 comprises a plurality of facets/faces thatinclude or otherwise incorporate a reflective surface such as a mirror.The disk 1112 and the rotating mirror 1114 can be used to create lightpatterns such as the light pattern 136A, 136B shown in FIGS. 6A and 6B.The emitted light 1122A and 1122B is transmitted out of the housing 1102of the measurement device 1100 towards objects. A portion of the emittedlight reflects off the objects and returns through the cover 1106. Thislight, referred to as backscattered light, is represented in FIG. 24 byreference number 1126 (not all of the backscattered light is associatedwith a reference number in FIG. 24). The backscattered light 1126 isreflected by the rotating mirror 1114 through the disk 1112 and towardsthe focusing apparatus 1118.

The focusing apparatus 1118 is an optical element such as a lens thatfocuses the backscattered light 1126 towards the stationary mirror 1114and ultimately to the detector 1120. The focused backscattered light1126 is reflected by the stationary mirror 1114 towards the detectors1120A and 1120B. The particular shape, size, position, and orientationof the focusing apparatus 1116 in the measurement device 1100 can dependon, among other things, the position of the detector(s) 1120A and 1120B,where the path(s) at which backscattered light 1126 is directed withinthe housing 1102, and space constraints of the measurement device 1100.The focusing apparatus 1118 includes an aperture to allow the emittedlight 1122A and 1122B to pass through the focusing apparatus 1118towards the disk 1112.

In response to receiving the focused backscattered light, the detectors1120A and 1120B generates one or more sensing signals, which areultimately used to detect the distance and/or shapes of objects thatreflect the emitted light back towards the measurement device 1100 andultimately to the detectors 1120A and 1120B.

In certain embodiments, the measurement devices described above areincorporated into measurement systems such that the systems include oneor more measurement devices. For example, a measurement system for anautomobile may include multiple measurement devices, each installed atdifferent positions on the automobile to generate scanning lightpatterns and detect backscattered light in a particular direction of theautomobile. Each measurement device may include circuitry for processingthe detected backscattered light and generating signals indicative ofthe detected backscattered light, which may be used by measurementsystems to determine information about objects in the measurementdevices' fields of view.

Various methods can be carried out in connection with the measurementdevices described above. As one example, a method for generating ascanning light pattern using various measurements devices describedabove includes rotating a disk having prisms; rotating a reflectingapparatus having multiple reflective facets; directing light from alight source through the rotating disk to create a first light pattern;and reflecting, via the rotating reflecting apparatus, the first lightto generate the scanning light pattern described above and schematicallyshown in various figures. Components of the other measurement devicesdescribed herein can be used in various methods to generate scanninglight patterns and detect backscattered light from the scanning lightpatterns.

Various modifications and additions can be made to the embodimentsdisclosed without departing from the scope of this disclosure. Forexample, while the embodiments described above refer to particularfeatures, the scope of this disclosure also includes embodiments havingdifferent combinations of features and embodiments that do not includeall of the described features. Accordingly, the scope of the presentdisclosure is intended to include all such alternatives, modifications,and variations as falling within the scope of the claims, together withall equivalents thereof.

We claim:
 1. An apparatus comprising: a first detector and a seconddetector; a first light source configured to emit light and a secondlight source configured to emit light; a disk having a set of prisms,being configured to rotate around a rotation axis, arranged to receiveand direct the emitted light, and arranged to receive and directbackscattered light; a reflecting apparatus having multiple reflectivefacets, being configured to rotate, arranged to reflect the emittedlight, and arranged to reflect the backscattered light, wherein thefirst light source is arranged to direct the emitted light to a firstfacet position, wherein the second light source is arranged to directthe light to a second facet position; and a focusing apparatus arrangedto focus the backscattered light from the disk towards the firstdetector and the second detector.
 2. The apparatus of claim 1, whereinthe focusing apparatus is a curved mirror or a lens.
 3. The apparatus ofclaim 1, wherein the focusing apparatus is a curved mirror, theapparatus further comprising: a lens arranged to focus the backscatteredlight reflected by the curved mirror towards the first detector and thesecond detector.
 4. The apparatus of claim 1, wherein the focusingapparatus includes an aperture through which the emitted light passes.5. The apparatus of claim 1, wherein a number of reflective facets ofthe reflecting apparatus is 6-12.
 6. The apparatus of claim 1, whereinthe disk includes multiple sets of prisms each with prisms havingdifferent prism angles from the other sets of prisms.
 7. The apparatusof claim 1, wherein the reflecting apparatus is arranged to rotatearound the rotation axis or an axis parallel to the rotation axis. 8.The apparatus of claim 1, further comprising: a housing forming aninternal cavity, wherein the first detector, the second detector, thefirst light source, the second light source, the disk, and the focusingapparatus are positioned within the internal cavity.
 9. The apparatus ofclaim 1, further comprising: a third light source configured to emit,wherein the third light source is arranged to direct the emitted lightto a third facet position.
 10. The apparatus of claim 1, furthercomprising: a third detector, wherein the focusing apparatus arranged tofocus the backscattered light from the disk towards the third detector.11. A method for generating a first scanning light pattern and a secondscanning light pattern, the method comprising: rotating a disk havingprisms around a rotation axis; rotating a reflecting apparatus havingmultiple reflective facets; directing light from a first light sourcethrough the rotating disk to create a first light pattern; directinglight from a second light source through the rotating disk to create asecond light pattern; and reflecting, via the rotating reflectingapparatus, (1) the first light pattern to generate the first scanninglight pattern and (2) the second light pattern to generate the secondscanning light pattern.
 12. The method of claim 11, further comprising:receiving, at a first detector and a second detector, backscatteredlight of the generated first and second scanning light patterns that isreflected by the rotating reflecting apparatus and that passes throughthe disk.
 13. The method of claim 12, further comprising: focusing, witha focusing apparatus, the backscattered light that has been reflected bythe rotating reflecting appataus and that has passed through the disktowards the first detector and the second detector.
 14. The method ofclaim 11, wherein the reflecting apparatus is rotated around therotation axis or an axis parallel to the rotation axis.
 15. An apparatuscomprising: a detector; a light source configured to emit light along anemission axis; a disk having prisms, being configured to rotate around arotation, arranged to receive and direct the emitted light, and arrangedto receive and direct backscattered light, wherein the disk is the onlydisk within the apparatus, wherein the rotation axis is perpendicular tothe emission axis; a stationary reflecting apparatus arranged to reflectthe emitted light and arranged to reflect the backscattered light; and afocusing apparatus arranged to focus the backscattered light towards thedetector.
 16. The apparatus of claim 15, further comprising a lensoptically positioned between the disk and the stationary reflectingapparatus.
 17. The apparatus of claim 16, wherein the lens is opticallypositioned between the disk and the detector.
 18. The apparatus of claim17, wherein the lens is optically positioned between the light sourceand the disk.
 19. The apparatus of claim 16, further comprising apyramidal mirror having multiple reflective facets, being configured torotate, arranged to reflect the emitted light, and arranged to reflectthe backscattered light.
 20. The apparatus of claim 19, wherein the diskis optically positioned between the lens and the pyramidal mirror.